Fauci tells Congress the U.S. could have enough coronavirus vaccine doses for every American by April

White House coronavirus advisor Dr. Anthony Fauci told Congress on Wednesday "it might take some time" for FDA-approved inoculations for Covid-19 to become available because of the "rigorous clinical testing required" to develop a safe and effective vaccine.

Still, he added, there is "growing optimism" that scientists will find one or more safe and effective vaccines by the end of the year or early 2021.

In prepared remarks for delivery at a Senate Appropriations Subcommittee hearing, Fauci touted vaccines by Moderna, Pfizer, AstraZeneca and Johnson & Johnson, which announced earlier in the day that it began a phase three trial testing of its vaccine. J&J is the fourth drugmaker backed by the Trump administration's Covid-19 vaccine program Operation Warp Speed to enter late-stage testing, behind Moderna, Pfizer and AstraZeneca.

Fauci said a fifth vaccine, by Novavax, is expected to begin a late-stage testing in October. 

"A safe and effective vaccine for SARS-CoV-2 will be essential to stopping the spread of infection, reducing rates of morbidity and mortality, and preventing future outbreaks," the director of National Institute of Allergy and Infectious Diseases said. 

President Donald Trump has insisted that the U.S. could have a safe and effective vaccine by the end of October and have enough vaccine doses to inoculate every American by April. The president's comments are at odds with his own health officials and have fueled concerns that politics, not science, will influence the vaccine approval process.

Fauci has said there is "no guarantee" that scientists will find a safe and effective vaccine. If they do find one, he has said the U.S. can start thinking about getting back to some form of normality" toward "the middle to end of 2021."

At a Senate hearing last week, the head of the Centers for Disease Control and Prevention said he expects vaccinations to begin in November or December, but in limited quantities with those most in need getting the first doses, such as health-care workers and the elderly. The CDC director, Dr. Robert Redfield, said it will take about "six to nine months" to get the entire American public vaccinated and that the U.S. would be able to resume "regular life" by the third quarter of next year. 

In his remarks scheduled for Wednesday's hearing, Redfield said the agency continues to work to prepare public and private health systems to deliver a safe and effective vaccine if and when one is available.

He said the CDC is working closely with the Advisory Committee on Immunization Practices, an outside group of medical and public health experts who develop recommendations on the use of vaccines in the United States. The committee is scheduled to hold a meeting on vaccines in October.

Redfield promised Congress that any CDC recommendation about who should get a vaccine and when will be "grounded in guidance from the country's foremost experts on immunization science."

He said some some state and local health departments have already built infrastructure that would address vaccine response needs. In Chicago, for example, health officials developed an app to communicate directly with residents who may be positive with the virus, he said. The app has since been adapted and now allows users to register to receive a vaccine once one becomes available, he added. 

While it remains unclear how long the pandemic will last, Covid-19 "activity will likely continue for some time," Redfield said.

He urged Americans to get a flu vaccine as the circulation of the coronavirus and influenza "could place a tremendous burden on the health care system."